Whipstock



l.. c. KELLY WHIPSTOGK March 14, 1933. l

Filed NOV. l, 1929 vfzmolzzar Laurenfflelly.

iiorlzey.

Patented Mar. 14, 1933 PATENT OFFICE LAURENCE C. KELLY, OF BEVERLY HILLS, CALIFORNIA WHIPSTOCK Application led November 1, 1929. Serial No. 403,968.

This invention relates to whip-stocks such as are used in well drilling operations for deflecting a drill or cutter to avoid an obstruction in the welllbore or casing.

In drilling wells it sometimes occurs that the bit meets an obstruction, or the lower end of the well bore becomes obstructed by the dropping of a bit or other tool therein; and in such cases the well bore must be side tracked to avoid the obstruction. For this purpose it is common practice to lower a whip-stock in the well bore down to the obstruction, the upper end of the whip-stock having a diagonal deflecting surface that forms a deflecting guide for the drilling tool. After anchoring the whip-stock in position, the drill is lowered and upon meeting the inclined upper surface of the whip stock is deflected laterally and cuts a slanting bore through the side of the original well bore, thus passing downwardly to the side of the obstruction.

One of the greatest diiiiculties encountered in the above outlined practice resides in planting the whip-stock in a properly centered and upright position, and in securely anchoring it in that position so that it will neither tilt or rotate when met by the drill.

One common practice for planting and anchoring the whip-stock in position has been simply to drop the whip-stock in the wel] hole, and then follow it with a charge of cement, which cement is intended to ll in` around the sides of and under the whip-stock to form aV substantial foundation therefor. Among the diiiiculties encountered in this practice are the facts that no means are provided for guiding the whip-stock into position or for holding it in position while it is set in cement, with the result that it often comes to rest and is sct at an undesirable angle. Further, it is often extremely difficult if not entirely impossible to get the change of cement down through the usual water and mud to the base of the whip-stock.

It is an object of my invention to provide means for anchoring a whip-stock in cement in such a manner as to insure that the whip-- stock is supported in an upright position and that the cement forms a firm foundation under and around the sides thereof.

I accomplish this object by providing means whereby the whip-stock can be attached to a string of pipe to be lowered thereby, and by providing a longitudinal bore through the whip-stock communicating with the bore of that pipe and .through which cement may be introduced. In practice, the whip-stock is lowered on the end of the pipe string, and a measured charge of cement is then forced down through the pipe string and out of the lower end of the whip-stock, where it emerges under pressure to completely surround the whip-stock and provide a substantial setting therefor. When the cement has been discharged the pipe string is detached from the whip-stock and withdrawn, after which the side tracking operations are carried out in the usual manner well known to the art.

The above and other objects and features of the invention will best be understood from the following detailed description of a present preferred embodiment thereof, reference for this purpose being had to the accompanying drawing, in which Fig. 1 is a vertical longitudinal section through'the whip-stock showing it attached to a pipe string above the obstruction which is to be avoided; and

Fig. 2 is a plan view looking down on the whip-stock proper.

Referring now to thel drawing, the numeral 10 designates generally the well bore in the lower endA of which is an obstruction,

.illustrated in the present case as a lost tool 11. If the occasion requires, the first operation may consist in filling in cement above the lost tool to form a solid support, indicated at 11a, upon which the whip-stock may rest at its lower end. This cement filling may be taken as typical of any suitable support for the whip-stock. The whip-stock, generally designated by the numeral 12, is lowered to the support 11a by means of a string of pipe 13. There rotary operations are in use, the drill pipe will usually be used for this purpose. The lower end of the drill pipe is coupled to a tool joint 14 to which is threaded a carrier fitting 15 for the whipstoclr proper. The whip-stock proper comprises an elongated bar, which may be rectangular in cross-section, as shown in Fig. 2, or of any other convenient form, having a beveled upper end providing a slanting drill deflecting surface 17. Carrier fitting 15 has a lower tapered end providing a complementary lower slanting surface 18 in contact with surface 1'7, and the whip-stock is supported from fitting 15 by means of light bolts 19 passing through th-e tapered overlapping ends. The bolt heads are preferably countersunk in the side of the whip-stock body so that they will not rub against the side of the well bore or the well pipe as the whipstock is lowered.

Fitting 15 and whip-stock 12 are drilled with a longitudinal circulation bore 2O forming a continuation of the bore of the rotary drill pipe. The lower end of bore 2O is then closed by a plug 32. If found more convenient in manufacture, bore 2O need not extend through the bottom end of the whip-stock and the plug 32 will then not be required.

The lower end of fitting 15 is counterbored at 24 and tapped to take a sleeve 25 which `extends down into a corresponding counterbore 26 in the whip-stock and rests at its lower end upon a rubber gasket 27 therein. There is thus provided a cheaply manufactured fluid tight joint for bore 20 Vbetween the litting 15 and the whip-stock proper, eliminating what would otherwise be necessary in machining the two slanting faces 17 and 18.

The whip-stock is lprovided with a lower reduced section 30 drilled with a number of lateral circulation holes 3 1 through which fluid in bore 20 can be discharged around the sides of the whip-stock. These lateral circulation holes, which are preferably at the lower end of the whip-stock body, as shown, are of a total area practically equivalent to the area of the main vertical circulation bore 20.

The lower section 30 of the whip-stock is provided with grooves 34 to aid in bonding the whip-stock in the cement into which it is to be set.

The method of setting the whip-stock in cement is as follows: After lowering the whip-stock to the desired point near or'above the obstruction by means of the drill stem, a. measured charge of cement is forced down through the drill stein and circulation bore of the whip-stock, and finally out through the circulation passages 31 to illin around the lower end of the whip-stock, as indicated at 38 in the drawing. If a pipe of smooth interior is used, a loose fitting plug can of course be sent down on top of the cement charge; and the arrival of the plug at the lower end of the whip-stock and consequent closure of the discharge openings will hold the pressure and thus signal to th-e surface the fact that the cement charge is out. Then the drill pipe is released from the whip-stock by allowing the weight of the string of drill pipes to come upon the whip-stock, which causes bolts 19 and sleeve 25 to shear olf so that the drill pipe can then be drawn up.

rlfhe following operations of drilling against the upper deiecting surface 17 of the whip-stock so that the drill is side tracked about Q' 'a obstruction are well understood in the art and need no further description.

N o difliculty ensues if the filled in cement should rise above the level indicated in the drawings to a point above the upper end of the whip-stock, for the bit will merely drill down through the surplus cement and when it strikes the upper surface of the whip-stock will be turned aside as before.

It will be now seen that I have provided a whip-stock which is supported in upright position until cemented in, and that I have provided positive and elfeetive means for surrounding the lower end of the whip-stock with a solid bed of cement. Itis thus a characteristic feature of the invention that the device can not only be accurately placed, but that there is great assuredness of its being solidly set in cement. Heretofore when it has been endeavored simply to pour cement down around a whip-stock it has been the common experience that the cement will not pass down below the head of the whip-stock because of the heavy mnd which is so to speak entrapped around and below the whip-stock. 'By deliv- I ering the cement initially under pressure to a point or points around the lower end of the whip-stock it is assured that the whip-stock is well set, all of the mud around its base being displaced by cement. The cement will first envelop the lower end of the whip-stock and then flow upwardly around it. Thus the whipstock is given a perfect foundation at its lower end; and the downwardly facing shoulder at 33 just under the head of the whip-stock provides additional support for it in the set cement.

Moreover, since the whip-stock body is of a cross-sectional form which will notpermit of its turning in its solid cement setting, there is no possibility of losing the side-track bore by rotation of the whip-stock at a time when the drill stem is withdrawn. And as a further feature, due to the fact that the whipstock is held in a centered position while being set in the cement, its cross sectional area can be substantially less than has heretofore been possible.

It will be understood the drawing and dc- 'scription are to be considered merely as illustrative of and not restrictive on the broader claims appended hereto,l for various changes in design, structure and arrangement may be made without departing from the spirit and scope of said claims.

i lateral discharge Y,passages from the bore out through the sides of the body.

2. A combination of a whip-stock comprising an elongated body having a cutter deflecting upper end, a longitudinal course down into the body from said upper end and adapted at its upper end for communication with a pipe string, and lateral discharge passages from said course through the side walls of the body near its lower end; and detachable means for connecting said body with a pipe string.

3. The combination of a whip-stock comstock, a shear bolt assing through the overlapped tapered en s of the fitting and whip-A stock, the upper end 'of said fitting being adapted for connection with a pipe string, and there being a longitudinal course through the fitting and through the whip-stock body which communicates with the bore of the pipe string, and a shearable sleeve fitted into said bore at the juncture of the fitting and whipstock body providing a fluid tight joint thereat.

7. A whip-stock, comprisingan elongated body having a cutter deilecting u per end, a reduced lower section providing a downwardly facing shoulder onthe whip-stock body, a longitudinal course extending from the upper end down into the lower reduced section of the body and adapted at its upper end for communication with a pipe string, and lateral prising an elongated body having a Cutter dedischarge passages from said bore out through fleeting upper end, a longitudinal course down into the body from said upper end, and lateral discharge passages from said course through the side walls of the body near its lower end; and detachable means for connecting said body with a pipe string, said means having a course providing communication between the bore of the pipe string and the longitudinal course of the whipstock.

4. The combination of a whip-stock comprising an elongated body having a slanting upper surface adapted for lateral deflection of a cutter, and a fitting having a complementary slanting lower surface resting face to face with the slanting upper surface of the whip-stock and detachably secured to said whip-stock, the upper end of said fitting being adapted for connection with a pipe string, there being a longitudinal bore through the fitting and into the whip-stock which communicates with the bore of the pipe string, and discharge passages from said bore out through the side walls of the whip-stock body.

5. The combination of a whip-stock comprising an elongated body having a tapered upper end providing a slanting surface for lateral deflection of a cutter, and a fitting having a tapered lower end providing a complementary slanting surface adapted to rest ace to face with the upper surface of the whipstock, a shear bolt passing through the overlapped tapered ends of the fitting and whipstock, the upper end of said fitting being adapted for connection with a pipe string, and there being a longitudinal course through the fitting and whip-stock body which communicates with the bore of the pipe string.

\ 6. The combination of a whip-stock comprising an elongated body having a tapered upper end providing a slanting surface for lateral deflection of a cutter, and a fitting having a tapered lower end providing a complementary slanting surface adapted to rest face to face with the upper surface of the Whipthe side walls of said lower reduced section. In witness that I claim the foregoing I have hereunto subscribed my name this' 26 day of October, 1929.

LAURENCE C. KELLY.v 

